1. Field of the Invention
The present invention relates to an apparatus for generating a massaging water stream by forcedly circulating a water in a bath-tub, said water stream having a sufficient power for massaging a user in the bath-tub.
2. Description of the Related Art
Heretofore, there has been proposed an apparatus for generating a water stream within a bath-tub, said water stream having such velocity and flow rate that a user in the bathtub is subjected to impact by the water stream to perform a massage. Such a massaging water stream can be effectively used for attaining various functions such as beauty, health and physical practice.
In a known massaging water stream generating apparatus, a motor and a propeller coupled with a driving shaft of the motor are arranged within a bath-tub, and therefore the apparatus is liable to be complicated in construction and large in size. For attaining a sufficient massaging effect, it is generally required to generate the water stream having a velocity not less than 2 m/sec. Then, it is necessary to use a propeller having a relatively large diameter. In order to drive such a large propeller, it is required to use the large motor of higher power. Then, the apparatus produces very large vibration as well as a very large noise of about 90 dB.
Moreover, in order to operate the propeller at a high efficiency, it is advantageous to form a rectilinear portion having a low resistance against the stream of water behind the propeller. However, in the known apparatus, it is impossible to form such a rectilinear portion behind the propeller, and thus an efficiency of the propeller is relatively low. Further, since the motor is embedded in the water, it is necessary to provide a water seal between the driving shaft and the motor housing. This would make the maintenance difficult and expensive, because the water seal has to be replaced at regular intervals. Moreover, in order to protect the user from being damaged or injured by the propeller rotating at a high revolving speed, a suitable member such as a mesh has to be provided around the propeller. It is apparent that this protection member increases the resistance against the massaging water stream. Due to the above mentioned various problems, the known apparatus could not generate a powerful water stream having a sufficient massaging function without producing undesired vibration and noise.